Power management systems are used to selectively provide power to various types of power consuming loads. Some power management systems include a variety of different power sources.
As an example, some conventional power management systems are used in remote locations and include a primary power source (e.g., a wind, solar or hydro power source) and a secondary power source (e.g., a generator that operates when load demand cannot be met by the primary power source). The primary power sources in such systems typically either (i) operate the loads directly; (ii) charge a battery that operates the loads when the primary power source is unavailable; or (iii) a combination of both. The secondary power source is then used to (i) operate the loads directly when the primary source is unable to meet demand; and/or (ii) charge the batteries when the batteries require charging.
One of the drawbacks with some existing power management systems is that they typically include a constant speed generator that is often oversized for a particular application. Therefore, the constant speed generators that are typically used in such applications usually operate below peak efficiency.
Another drawback with existing power management systems is that they are often unable to charge the battery while the generator is being used to provide power to a load. Therefore, in situations where the primary power source becomes unavailable for extended periods of time, the battery may be damaged.
Some power management systems may try to overcome such a drawback by starting the generator much sooner in order to prevent damage to the battery. However, starting the generator sooner in such systems underutilizes the battery and undesirably causes the generator to burn fuel unnecessarily.
Therefore, a need exists for a power management system that includes a variable speed generator. In addition, the power management system should be able to charge the battery while the generator is being used to provide power to a load.